1. Field of the Invention
The present invention relates to a coil device as an antenna, for example.
2. Description of the Related Art
To protect a coil device used for antennas from impact including vibration, it is considered to house a bobbin with a coil portion in an outer case and seal around the coil device with a potting resin or so. The entire periphery of the bobbin is preferably sealed with resin in the outer case. Thus, as shown in Patent Document 1, a convex portion is arranged on an outer periphery of the bobbin to be sealed with resin and abuts against an inner wall of the outer case, and a space between the bobbin and the outer case is arranged so that a sealing resin reaches the space, for example.
Since the bobbin is constituted by a hard epoxy resin, however, the convex portion arranged on the outer periphery of the bobbin and the inner wall of the outer case are in contact, and impact resistance characteristics may be deteriorated. High-level impact resistance characteristics are required particularly for coil devices used in auto industry or so, and sufficient impact resistance characteristics are hard to be obtained by a conventional coil device structure.
Patent Document 1: JP 2014-175363A